What is a ventricular septal defect?

A ventricular septal defect (VSD) is a congenital heart defect. This means that your baby is born with it. A VSD is a hole in the  wall (septum) that separates the 2 lower chambers of the heart (right and left ventricles). VSDs are the most common type of congenital heart defect.

The heart has 4 chambers: 2 upper (atria) and 2 lower (ventricles). Blood that is high in oxygen flows from the left atrium to the left ventricle and out to the body, where the vital organs use the oxygen. Blood with less oxygen flows from the right atrium to the right ventricle and out to the lungs. In the lungs it picks up more oxygen.

Normally. the septal wall prevents the mixing of blood between the two ventricles of the heart. A VSD allows oxygen-rich (red) blood to pass abnormally from the left ventricle through the opening in the septum. Then it mixes with oxygen-poor (blue) blood in the right ventricle.

A large VSD can cause high pressure in the blood vessels in the lungs. The higher pressure can lead to lower oxygen levels in the body. If your child has a larger VSD, he or she may need some type of repair. Babies and children with larger VSDs often have symptoms such as breathing faster and harder than normal. Very small holes in the ventricular septum may not let much blood pass between the ventricles. In these cases, the heart and lungs don’t have to work harder. Sometimes these small holes will close up on their own.

There are different types of VSD. The type your child has depends on which part of the wall between the ventricles is involved. The size of the opening or hole also varies.

What causes a VSD?

VSD may occur more often in some families. This is because of gene problems. Most of the time, doctors don't know the cause of VSD.

What are the symptoms of a VSD?

Your child may have symptoms from birth. Or your child may not have symptoms until they are a little older. The size of the opening or hole affects how severe your child’s symptoms are. So does the age at which your child first has symptoms. If the hole is small, the only sign may be a heart murmur that your healthcare provider hears with a stethoscope. With a larger opening, the heart and lungs have to work harder.  

This can cause symptoms such as :

• Tiredness

• Fast breathing

• Trouble breathing

• Pale skin

• Rapid heart rate

• Enlarged liver

• Poor feeding or tiring while feeding

• Poor weight gain

Symptoms can occur a bit differently in each child. The symptoms of VSD may also be similar to symptoms of other conditions. Make sure your child sees the healthcare provider for a correct diagnosis.

How is a VSD diagnosed?

Your child's healthcare provider may suspect a problem when they hear an abnormal sound (heart murmur) when listening to your child's heart with a stethoscope. If this happens, the healthcare provider may refer your child to a heart doctor for children (pediatric cardiologist).

The heart doctor will check your child. He or she will listen to your child’s heart and lungs. The details about the murmur will also help the heart doctor make the diagnosis. 

The heart doctor may do tests to confirm the diagnosis. The tests your child has depends on his or her age and condition, and the doctor’s preferences.

How is a VSD treated?

Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.

A small VSD may close on its own as your child grows. Some small defects don’t close on their own, but they still don’t need treatment. A larger VSD often needs to be fixed with surgery or through cardiac catheterization. Once a child is diagnosed with a VSD, their heart doctor will check the defect regularly to see if it’s closing on its own.

What are possible complications of a VSD?

Complications of an untreated VSD include:

• Lung problems

• Heart failure

• Irregular heart rhythms (arrhythmias)

• Heart valve problems

• Poor growth and development

Living with a VSD

When should I call my child's healthcare provider?

Call the healthcare provider if your child has:

• Trouble breathing

• Trouble eating

• Any new symptoms

Key points about VSD

• A VSD is an opening in the dividing wall between the 2 lower chambers of the heart.

• The size of the opening affects how severe your child’s symptoms are.

• Small VSDs may close on their as your child grows. If your child has a larger VSD, he or she will likely need surgery or a cardiac catheterization to fix it.

• Most children whose defects close on their own or who have VSD repairs will live normal, healthy lives.

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:

• Know the reason for the visit and what you want to happen.

• Before your visit, write down questions you want answered.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.

• Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.

• Ask if your child’s condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if your child does not take the medicine or have the test or procedure.

• If your child has a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.